I see that your account as it is now, has done question on it which you deleted yourself on the 11th of May 2011.
Apart from that, I see no activity from your account at all. Which means one of the following:
You have multiple accounts. I have done a quick search and can only find the account you posted this question from, but if you used a different Open ID, Email address or display name I might have trouble finding your other account.
You're on the wrong site. This is unlikely because you specifically mention Server Fault in your question, but it does happen! I see that you asked a question on Stack Overflow on the 11th of March. Could that be it?
Gremlins ate your question (highly unlikely).
I don't suppose you remember what your missing question was about? If we can track down the question, then we can find what happened to it.
Content is never permanantly deleted from the site, it always hangs around and can be undeleted, if we can just find it.